GYSFLASH 123-12 CNT (5M cables) is a 120A high power stabilised supply incorporating Inverter technology with 4 functions : 

• Charging: for 12 V Lead or Lithium batteries from 5 to 1500 Ah.

• Diagnostic: supports up to 120 A vehicule batteries in diagnostic phase, in maintenance workshops.

• Showroom: provides power compensation when using the electrical accessories of a demonstration vehicle.
It also manages the optimal charging of the battery.

• Tester: Allows you to check the battery voltage, evaluates the starting system (starter + battery) and the condition of the vehicle’s alternator

https://www.
gys.
fr/pdf/datasheet/uk/025677.
pdf